Hi Jason,
a modeller's servo seems to be fine: it has a high torque and while
powered, it keeps its position actively. Disadvantages are their price
and the fact they are controlled by AF PWM / PPM (unless one modifies
them, of course).
A cheap source are scrap FDDs and CD-ROMs: there are 2 - 3 classic and
stepper motors in each of these animals. They are used for positioning
the head, rotating the media, ejecting the CD etc. It needs a bit of
skill and effort to put them into new life, though.

BR from Ivan

(Jason Hsu) wrote in message . com...
Has anyone here used a motor to control a potentiometer or variable
capacitor? (An automatic tuner would be such an application.)

What type of motor do you use? Servo? Stepper? Something else?
What do I need to look for in a motor?

Jason Hsu, AG4DG